Where do you live? We had outdoor cats live until they were 19 and 17, both passed from age-related illness. Relatively calm neighborhood away from any heavy traffic, granted; but still.
For one, the average area of a house in the USA seems to be above 2000 square feet, whereas here in the UK it's more like 750 or so.
It feels worse for the animal to be cramped in a tiny space all their life, so we let them outside. Also there are no predators apart from the occasional domesticated dog, so it's safer. The biggest risk is traffic, which is dependent on where you live.
The bird thing brought up every time is weird to me, because no one seems to care about birds until cats are part of the conversation, suddenly birds are the most important part of the ecosystem.
Of the current cat with free-ish outdoor access: Last year birds accounted for 3.6 percent of all recorded catches (5/138). This year birds are 1.7 percent of all recorded catches (1/58). And all of the birds I've seen caught first knocked themselves out striking windows, or flew inside the house via open door and injured themselves trying to escape in panic. The healthy ones don't let cats near them at all.
Of the prior cat, zero birds over 9 years. Of the cat before that, maybe 1 or 2 birds over 18 years.
Of course anecdotes aren't data etc, but, the impact of data is its story, and anecdotes direct and constrain the collection and analysis of data.
We've had no cats that lived between 3 and 16 years.
I have no idea why. To some degree you could get a sense which category a cat was in within the first year or so.
If I were to guess I think a cat will probably have a shorter life span in a city. More cars and more opportunities to get infected with diseases from other cats.
Those cats (or people) who make it through that crisis will gain some hard humility forever more and seem to go on for a long time after. Those who don't, well, obviously that's it. I had two big male cats back in the 90s, who being tough young males naturally once they got to 2-3 years old felt pretty confident. First of them sadly vanished and never saw him again. The second a few years later got into some fight or flight with/from something, I don't know what, but there were shrieks. But he escaped/fought and I found him. Forever after he was very careful, he'd go out the door onto the porch and whereas before he'd just instantly head off, after he'd immediately sit down and observe/listen for a good long while first. He lived to 21 years old. Another outdoor/indoor lived to 19.
It is truly hard to take the risk, but they're so much happier for it. We all reach the same end in the end, so I feel very strongly that there are limits to how far one should take "being safe". And there are good ways to massively reduce the bird issue. I love birds as well, but 3-5 caught per year when I'm feeding and support orders of magnitude more birds than that seems acceptable.